XML Validator
Validate XML syntax
What Is This Tool?
The XML Validator checks whether a document is well-formed XML — correctly nested tags, matching quotes, valid characters and a single root element. It shows a clear Valid or Invalid result and, when invalid, the browser parser's detailed error message. Everything runs locally using the built-in DOMParser.
How to Use
Paste your XML into the input box.
Click Validate.
Check the Valid / Invalid status.
If invalid, read the error detail to locate the problem.
Features
- Clear Valid / Invalid status indicator
- Detailed parser error message on failure
- Separate valid and invalid example documents
- Copy the validation status as text
- 100% client-side — nothing leaves your browser
Examples
Valid:
<catalog><item id="1"><name>Widget</name></item></catalog>
Invalid (mismatched tag):
<catalog><item id="1"><name>Widget</item></catalog>
Common Use Cases
- Checking a config, feed, or SOAP payload is well-formed before use
- Debugging why an XML parser in another tool is rejecting a file
- Verifying hand-edited or generated XML before committing it
- Teaching or learning what "well-formed" XML means
Frequently Asked Questions
Is my XML uploaded anywhere?
No. Validation happens locally in your browser using the built-in DOMParser. Nothing is sent to a server.
Does this validate against a schema (XSD/DTD)?
No, it only checks that the XML is well-formed, not that it conforms to a specific schema or DTD.
What counts as "well-formed"?
A single root element, properly nested and closed tags, correctly quoted attribute values, and no invalid characters.
What does the error message tell me?
It's the browser's own parser error, which usually names the problem (such as a mismatched tag) and its approximate location.
Can I copy the validation result?
Yes, click Copy Status to copy the Valid/Invalid line (and error detail, if any) to your clipboard.